Seasonal incidence of major insect pests of mustard and their natural enemies

Abstract

A field experiment was conducted at research farm of College of Agriculture, Tikamgarh to assess the seasonal incidence of major insect pests of mustard crop and their natural enemies and its correlation with weather parameters. The incidence of mustard aphid, painted bug and flea beetle were started during 47th SMW and attained their peaks during 5th, 8th and 52nd SMW respectively. While the activity of C. septumpunctata and D. rapae were started from 4th SMW and reached its peak during 9th SMW respectively. Correlation studies revealed that aphid population was positive correlated with morning and evening relative humidity (r = 0.49, 0.44 respectively) and negatively correlated with maximum and minimum temperature, while significant and positive correlation was observed between population buildup of painted bug and maximum and minimum temperature (r =0.48 and 0.61). Whereas the flea beetle population exhibited significant positive correlation (r = 0.35 respectively) with maximum temperature and negatively correlated with morning and evening relative humidity to the level of significance. The correlation study between natural enemies and weather parameters revealed that the maximum temperature was significantly positive correlated (r = 0.76,) with Coccinella beetle population while morning and evening relative humidity were found to be negatively correlated (r = -0.92, -0.90 respectively). The Diaeretiella rapae population showed significant positive correlation with maximum, minimum temperature and rainfall (r = 0.42, 0.40, and 0.26 respectively), while morning and evening relative humidity were found to be negatively correlated (r = -0.11, -0.28 respectively).